Fix all remaining test failures

- archive::metadata: add failed_files to test_extract_result
- archive::tests: use TempDir for validate_extraction_path test
- provider::sqlite: fix db path using CARGO_MANIFEST_DIR/../data/auth.sqlite
- ssh_server::cipher: use AES-128 key (16 bytes) in test
- ssh_server::kex_complete: set kexinit payloads in test
- ssh_server::rsync_handler: fix file list flags (use 1, not 0)
- ssh_server::sftp_handler: expect SSH_FXP_VERSION at byte 4 (after length prefix)

All 135 tests now pass

markbase-core/src/ssh_server/kex_complete.rs

@@ -197,12 +197,16 @@ mod tests {
             &KexProposal::client_default(),
         ).unwrap();
         
-        let state = KexState::new(
+        let mut state = KexState::new(
             "SSH-2.0-OpenSSH_10.2".to_string(),
             "SSH-2.0-MarkBaseSSH_1.0".to_string(),
             kex_result,
         ).unwrap();
         
+        // Set minimal KEXINIT payloads (need at least 1 byte for packet type)
+        state.client_kexinit_payload = vec![20u8];  // SSH_MSG_KEXINIT type byte
+        state.server_kexinit_payload = vec![20u8];  // SSH_MSG_KEXINIT type byte
+        
         let shared_secret = vec![0u8; 32];
         let host_key = vec![0u8; 32];
         let client_pub = vec![0u8; 32];